Catheter-directed Approach Leads to Weight Loss
Left gastric artery embolization results in weight loss in patients, potentially leading to a role for interventional radiologists in helping stem the obesity crisis in the U.S., according to presenters of scientific paper at RSNA 2013.
"There may be a role for interventional radiology in bariatric medicine by modulating ghrelin levels using catheter-directed approaches," said Rahmi Oklu, M.D., Ph.D., an interventional radiologist at Massachusetts General Hospital (MGH), and an assistant professor at Harvard Medical School, Boston.
Ghrelin, an appetite-stimulating hormone, is primarily produced by cells found in the fundus of the stomach, which receives its primary vascular supply from the left gastric artery. Suppressing serum levels of ghrelin is a potential means of controlling body weight. Since the left gastric artery is sometimes embolized in interventional radiology procedures, researchers assessed post-procedural weight loss in patients after left gastric artery embolization.
"It is has been shown in animal models that embolization of the left gastric artery suppresses production of ghrelin by the stomach," said presenter Andrew Gunn, M.D., a radiology resident at MGH and Harvard Medical School. "Decreased production of ghrelin results in decreased appetite and weight loss."
Researchers retrospectively analyzed the electronic medical records of patients who underwent left gastric artery embolization for upper gastrointestinal (GI) bleeding from 2000 to 2012. Those records were compared to age-matched controls of similar patients who had undergone embolization of an artery other than the left gastric for upper GI bleeding. Patients' weights were recorded within four weeks prior to the embolization and within three months after the procedure; changes in weight were evaluated.
Nineteen patients with a mean age of 64.6 years were included in the experimental group, while 28 patients with a mean age of 58.7 years were included in the control group. The mean pre- and post-procedural weights in the experimental group were 184.1 lbs. and 170.8 lbs., respectively, representing a 7.3 percent decrease in body weight. The mean pre- and post-procedural weights in the control group were 177.3 lbs. and 173.6 lbs., respectively, representing a 2 percent decrease in body weight. The post-procedural weight loss of the experimental group was significantly greater than that observed in the control group (P=0.006).
Results demonstrate that patients lose significantly more weight after left gastric artery embolization than following embolization of other arteries for upper GI bleeding, suggesting that body weight can be potentially modulated via left gastric artery embolization in humans.
"We attempted to account for other variables in the patients' medical history that could explain weight loss as well," Dr. Gunn said. "We found that patients lost significantly more weight after left gastric artery embolization."
"Our findings in this small, limited number of cases is just the beginning," Dr. Oklu said. "These exciting results need to be rigorously investigated in larger trials."
The findings could offer hope for the more than 150 million Americans affected by obesity, many of whom rely on surgical options that can have serious complications, according to Dr. Gunn. "Results are promising," Dr. Gunn said. "Unfortunately, despite advances in both medical and surgical treatments, obesity rates continue to rise."